Astragalus gilviflorus

Aster hesperius

Willow Aster

Flower Heads

Saltcoats Regional Park
13-August-2006

Note that the key to the species in Budd's Flora requires the basal and lower stem leaves be sessile or subsessile. In fact, the lowermost leaves may be petiolate although these are often early deciduous. The keys in both Budd's Flora and Flora of Alberta require the leaves to be certain shapes (see below). In fact, the leaves vary from linear to broadly lanceolate. The key in Budd's Flora requires that the leaves usually be more than 10 mm wide. In fact, some of the leaves can be less than 10 mm wide, as some of the leaves on this site are. Budd's Flora requires that the involucre be 5-8 mm high, not 4-5.5 mm high. However, the involucre depicted in close-up photos on this site is barely more than 5 mm high. Finally, Budd's Flora requires the ray florets be blue, not white. In fact they can be white, blue, or even pink. Most commonly they are white.

Hesperius: Answers to key questions in Budd's Flora and Flora of Alberta leading to this species.

NOT [plants 50 cm tall, or more; stem stout, usually crimson-purple, hispid; leaves oblong to lanceolate, auriculate-clasping, entire or distantly serrulate]

plants perennial; NOT annual

plants with rootstocks or root crowns; NOT [plants with fibrous roots]

plants more or less pubescent, on the stem and branches in lines decurrent from the leaf bases; NOT [plants glabrous, except sometimes in the inflorescence

plant NOT rough pubescent

basal and lower stem leaves sessile or subsessile; NOT [basal and lower stem leaves petioled or narrowed to a petiolar base] (BF)

stem leaves sessile or somewhat clasping; NOT [stem leaves auriculate clasping]

leaves broadly linear to linear-lanceolate or lanceolate-ovate; NOT leaves narrowly linear (BF)

lower leaves linear, lanceolate or oblanceolate; NOT [lower leaf blades ovate to lanceolate, often cordate at base] (FOA)

leaves entire to subentire; NOT leaves serrate

leaves NOT silvery silky

leaves usually more than 10 mm wide; NOT [leaves seldom more than 6-7 mm wide] (BF)

leaves seldom more than 18 mm wide; NOT leaves 10-35 mm wide (BF)

heads generally more than 10; NOT [heads few, generally less than 10]; NOT [heads solitary or 1-3 on a stem]

involucre and peduncles NOT glandular

involucre 5-8 mm high; NOT involucre 4-5.5 mm high

outer bracts not foliaceous, not surpassing the inner; NOT [outer bracts (at least some) foliaceous, equaling or surpassing the inner]

involucral bracts generally herbaceous, at least above, usually not keeled; NOT [involucral bracts chartaceous, keeled, often crimson-edged]

bracts linear, lanceolate or oblong, all acute; NOT [bracts oblanceolate, the outer obtuse, appressed, well imbricate]

bracts mostly glabrous except the ciliate margins; NOT [bracts densely pubescent]

rays conspicuous

ray florets 20-40 in a head; NOT [8-15]

ray florets blue; NOT white (BF)

pappus single; NOT [pappus double, the inner series of firm long bristles, the outer series of bristles about 1 mm long]

Aster: Answers to key questions in Budd's Flora and Flora of Alberta leading to this genus. The answers do not match all species of Aster found in the Canadian prairies, but they do match this species.

taproot absent

juice watery; NOT milky

plants usually with leafy stems; NOT [ plants low, stemless, tufted]

plant is NOT as follows: [basal leaves mostly 1-6 cm long, linear to oblanceolate or spatulate, forming a dense rosette; plants with a well-developed taproot; and either densely caespitose, seldom more than 5 cm tall, the heads sessile among the leaves, or with stout, simple stems, 5-15 (25) cm tall, heads solitary, involucres 2-4 cm wide, bracts ciliate to pectinate or fimbriate, rays blue and achenes densely pubescent, obovate to triangular]

leaves appearing BEFORE the flowers

leaves NOT extending beyond the flowers

leaves alternate or basal; NOT opposite

basal leaves NOT cordate, NOT sagittate

involucral bracts either subequal and the outer leafy, or more commonly evidently imbricate, with chartaceous base and evident green tip, sometimes chartaceous throughout; NOT [involucral bracts subequal or more or less imbricate, often green in part, but neither definitely leafy nor with chartaceous base and herbaceous green tip]

bracts in several series; NOT [in 1 or 2 series]

receptacle naked

flower heads with florets both tubular and ray

ligulate flowers pistillate or neuter; NOT perfect

ray florets conspicuous

ray florets 10-50; NOT 50 or more

ray florets usually blue, purple, pink, or white; NOT yellow, NOT orange

stamens united to form a tube around the pistil

style branches ordinarily more than 0.5 mm long; NOT [style branches 0.5 mm long or less, or obsolete]

style branches lanceolate or narrower, acute or acuminate; NOT [style branches lanceolate or broader, acute to obtuse, or obsolete]

pappus of capillary bristles, at least in part; NOT [pappus of 1 or 2 short awns, a mere crown or none]

pappus composed of numerous hairs; NOT [composed of only a few hairs]